Copolymers containing 9-methylenefluorene



Patented Dec. 12, 1950 YMEB METHYLE J else! No Drawing.

This invention'relates to polymers and wwwmers oi. .9-me'thylenefluorene. More specifically,

, this invention'relates to a process for preparing copolymers of 9-methylenefluorene and polymerizable, unsaturated, organic compounds.

" Reindel and Ferrer (Berichte," volume 55 (1922), page 3313 described a process lor 'preparing monomeric Q-methyleneiluorene, and also described the preparation of a trimer of this monomer, ascribing the formula:

I to the monomer, and the formula:

C RH:

to the trimer.

We have now found that valuable copoiymers of 9-methylenefluorene and polymerizable. unsaturated, organic compounds may be prepared by copolymerizlng 9-methyienefluorene with one or more unsaturated, polymerizable, organic compounds.

It is, therefore, an object of this inl ention to provide new synthetic copolymers of Q-methylenefluorene and polymerizable, unsaturated, organic compounds.

A further object of this invention is to provide a process for preparing new synthetic copolymers which comprises copolymerizing a mixture of 9-methylenefluorene and one or more polymerizable, unsaturated, organic compounds. Other objects will become apparent from the consideration of the following description.

According to our process,-we prepare new. resinous, copolymjrfs by heating a mixture comprising 9-methy1enfluorene and one or more polymerizable, unsaturated, organic compounds.

Substantially, any organic compound containing unsaturation of the oleflnic type may be used E-S PATENT OFFICE S CONTAINING Nnrwoamm I Joseph B. Dickey and flarry W. Coover, Jr., Rochester, N. Y., salmon to Eastman Kodak Company, Rochester, N. Y., a corporation of New Application October 2, 1947, Serial N0. 777,580 I 12 Claims. (01.260-63) to prepare v, the copolymers of this invention. Since Qj-methyIenefluOrene-is a hydrocarbon and contains only the oleflnic-functional group, it is not prone to undergo undesirable side reactions which might'otherwise occur with other types of unsaturated compounds. Advantageously, we

may use such'compounds as acrylates, methacrylates, fumarates, maleates, acrylonitriles,

a-substituted acrylonitriles, acryl amides, vinyl sultones, vinyl sulfonamides, alkenyl' ketones, vinyl halides, or hydrocarbons containing oleflnic unsaturation.

The acrylates or methacrylates we may advantageously use in our process may be represented by the formula:

0 om=c-5-o a,

where R represents a member selected from the group consisting of hydrogen, methyl, or an acyloxy group, such as acetoxy, propionyloxy. butyryloxy, isobutyryloxy (i. e., an acyl group of an aliphatic carboxylic acid having 2 to 4 carbon atoms), and R1 representsa member selected from the group consisting of hydrogen, an alkyl group, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary and tertiary butyl (i. e. an alkyl radical represented by the formula CnH2n+l wherein n is a positive integer trom 1 to 4), an arylalkyl group such as benzyl, p-phenyl ethyl, etc, or an alkenyl group, such as vinyl. allyl, methallyhcrotyl, isopropenyl (i. e, an alkenyl group represented by the formula CnHZn-l where n is a positive integer from 2 to 4). Typical are methylacrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl a-methylacrylate, butyl acryiate, butyl methacrylate, benzyl acrylate, benzyl methacrylate, vinyl acrylate, vinyl methacrylate, aliyi acrylate, ally] methacrylate, methallyl acrylate, methallyl methacrylate, methyl-a-acetoxyacryiate, ethyl a-acetoxy acrylate, butyl c-butyryloxy acrylate, benzyl a-butyryloxy acrylate. etc.

The olefinic nitriles with which 9-methylenefluorene may be copolymerized may advantageously be represented by the formula:

where R2 represents a member selected from the group consisting of a hydrogen atom, a methyl group (CH3) or an acyioxy radical, such acetoxy. propionyloxy, butyryloxy, isobutyryloxy (i. e., an

essence acyl group of an aliphatic carboxylic acid having 2 to 4 carbon atoms). Typical are acrylonitrile, methyl acrylonitrile, c-acetoxy-acrylonite, abutyryloxy acrylonitrile, a-isobutyryloxy acrylo' nitrile, etc.

The olefinic'lretones which we may advantageously use in our process may be represented by the formula:

wherein R3 represenm a member selected from the group consisting of an alkyl group, such as methyl, ethyl, propyl, isopropyl, n=butyl, etc. (i. e., an alkyl group having the formula CnHZa-i-l where n is a positive integer from 1 to 4) or an allrenyl group such as vinyl, allyl, methallyl, isopropenyl, or crotyl, (i. e., an alkenyl group hav in the formula CnHZn-l where n is a positive integer from 2 to 4), and R4 is an alkenyl group such as vinyl, allyl, methallyl, crotyl, or lsopropenyl (i. e., an alkenyl group having the formula CIHZfl-l wherein n is a positive integer from 2 to 4). Typical are methyl isopropenyl ketone, methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, ethyl isopropenyl ketone, divinyl ketone, diisopropenyl ketone, diallyl ketone, dimethallyl ketone, etc.

The oleflnic acrylamides which we may use may be represented by the formula:

wherein R5 represents a member selected from the group consisting of hydrogen, a methyl group, or an acyloxy group, such as acetoxy, propionyloxy, butyryloxy, isobutyryloxy (i. e. an acyl group The maleates or fumarates which we may advantageously use may be represented from the formula:

wherein R6 and R1 each represents a member selected from the group consisting of hydrogen, an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary or tertiary butyl (i. e. an alkyl group having the formula CaH2n+1 wherein n is a positive integer from 1 to 4) an aralkyl group such as benzyl, p-phenyl ethyl, etc., or an alkenyl group, such as vinyl, allyl, methallyl, or crotyl (i. e. an alkenyl group having the formula CnHZn-l wherein n is a positive integer from 2 to 4). Typical are monomethyl maleate, monomethyl fumarate, dimethyl maleate, dimethyl fumarate, diethyl maleate, diethyl fumarate, dipropyl maleate, dipropyl fumarate, dibutyl maleate, dibutyl fumarate, diisopropyl maleate, diisopropyl fumarate, diisobutyl maleate', diisobutyl fumarate, dibenzyl maleate, dibenzyl fumarate, divinyl maleate, diallyl maleate, diallyl fumarate, dimethallyl maleate, dimethallyl fumarate, dicrotyl maleate, dicrotyl fumarate, etc.

The oleflnic carboxylic acid esters which we may use may be represented by the formula:

0 i -0 OH=OHa wherein Ra represents a member selected from the group consisting of hydrogen, an alkyl group such as methyl, ethyl, propyl, isopropyl (i. e. an aliwl group having the formula CnH2n+l where m is a positive integer from -1 to 3), an aryl group such as phenyl o-, m-, and p-methylphenyl (i. e. a mononuciear aryl group of the benzene series having 6 to 10 carbon atoms), or substituted aryl group such as chlorophenyl, carbovinyloxy phenyl 0 15-0 OH=OH etc. Typical are vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl chlorobenzoate and divinyl phthalate, etc.

The oleflnic hydrocarbons with which we may copolymerize Q-methylenefluorene may be represented by the formula:

RoCH=CHz where R9 represents a member selected fronithe group consisting of hydrogen, an aryl group such as phenyl, chlorophenyl, p-acetaminophenyl, an

wherein R10 and R11 each represents a hydrogen atom, or an alkyl group such as methyl, ethyl, propyl, butyl (i. e. an alkyl group having the formula CnHfln-l-l where n is a positive integer from 1 to 4), and R1: represents a member selected from the group consisting of hydrogen, a methyl group, or an ethyl group. Typical are vinyl sulfone amide, N-methyl vinyl sulfone amide, N-butyl-a-methyl vinyl sulfone amide. etc.

The vinyl halides which we may advantageously use may be represented by the formula:

where R1: represents a halogen atom such as chlorine, bromine, iodine, or fluorine, and Ru represents a member selected from the group consisting of a hydrogen atom, a methyl (cm-4 group, or a halogen atom such as chlorine, bromine, iodine, or fluorine. Typical are vinyl chloride, vinyl bromide, vinyl iodide, vinyl fluoride, isopropenyl chloride, isopropenyl bromide, vinylidene chloride, vinylidene bromide, etc.

Other unsaturated organic compounds can likewise be used to advantage in the process described below. Other oleflnic compounds containing functional groups such as 01, CN, N02, Br, 1'', etc. may be used without difliculty.

In accordance with our invention, we copolymerlze Q-methylenefluorene with one or more of the polymerizable unsaturated organic compounds listed above. The copolymerization is accelerated by heat and can be further accelerbutyl ganic peroxides (e. g. benzoylperoxide, acetyl peroxide, benzoyl acetyl peroxide, lauroyl peroxide, etc.). inorganic peroxides such as hydrogen peroxide, 'perborates (e. g. alkali metal'perborates) and persulfates (e. g. alkali metal persuliates).

The temperature tion is effected can vary from ordinary room temperauire to approximately 100 C. When volatile or vaporous unsaturated compoundsare beingused,'it may be advantageous to use superatmospheric pressures in order-to keep the reaction mixtures primarily in the liquid state. Ordinarily, we prefer to use a temperature of from 50 to 80 C. for optimum results. The copolymerization may be carried out by any of the Example 3.C'opolumer of methyl-racewayacrulate and Q-methvlenefluorene I 25 gms. of 9-m'ethylenefiuorene are mixed in- [as a catalyst. The product thus obtained had at which the copolymeriza-v common methods known to those skilled inthe art. For example, by 'the header emulsion method,'in which water or other medium in which the monomers are insoluble is employed as a dispersing medium, with or without emulsitying agents, such as theamines, etc. Thecopolymerization can also be effected in the presence of diluents such as benzene, toluene, di-

oxane, xylene, etc. which is advantageously a solvent for the copolymer.

Generally, any ratio of 9-methylenefluorene to the total organic, unsaturated compounds present in the reaction mixture may be used. When the reaction mixture consists of a tacky ethyl acrylate,

or semi-polymerized mixture the copolymer may be separated therefromby addition of a solvent which dissolves the monomers but not the polymers (e. g. methyl or ethyl alcohols). When the emulsion method of copolymerization is used, these steps are unnecessary since. the copolymer precipitates from the dispersing medium. Ad- I vantageously we can use from 2 to 95 mol-percent of Q-methylenefluorene and from 5 to 98 mol-percent 01' another unsaturated compound, although a more limited range, such as from 5 to 70 mol-percent of Q-mcthylenefiuorene and from to 95 moi-percent of another unsaturated compound, can be used. We can also use a ratio of Q-methylenefiuorene to unsaturated compound of from 5:1 to'l:5 parts by weight.

The following examples will further serve to characterize my invention.

Example 2.Copolzmzer of methyl methacrylate and Q-methylenefluorene resinous properties and was suitable for molding.

In lieu of the,methyl a-acetoxyacrylate other compounds such as ethyl-a-propionyloxy acrylate, etc. may be used.

Example 4.,'Cop0lymer of acrylonitrile and Q-methylenefluorene 5 grams'oi' 9-methylenefluorene and 25 gms. oi acrylonitrile are mixed and then dissolved in a 1:1 mixturepi acetic acid .,('l5 cc.) and dimethyl formamide. (dispersing agent), and the dispersion is polymerized by heat atf60 C. in the presence of benzoyl peroxide as a catalyst'.. The polymer' precipitates as a fine, colorless powder. when the polymer is dissolved in dimethyl formamide, a solution is obtained which may be used in. preparing fibers having good properties, the fibers being subsequently spun, if desired, through a suitable orifice into water. The resulting fiber is'then drafted 200-500% in hot air or oil. Other 'copolymers may be prepared by substituting a-acetoxyacrylonitrile, a-trifiuoroacetoxyacrylonitrile, a-butoxya'crylonitrile, a-cyanoa-methacryl'onitrile, a-cyanoacrylonitrile, etc. for the acrylonitrile'described above.

Example 5.-Copol1lmer of methyl vinyl ketone and Q-methylenefiuorene 5 grams oi. 9-methylenefluorene and 10 grams of methyl vinyl ketone are emulsified with 50 cc. oi. water in the presence of 0.5 gm. of polyvinyl alcohol as theemulsifying agent, and ammonium persulfate as a catalyst. After heating at 60-70 C. for approximately 24 hours, acetic acid is added,

' and a white product is obtained. This product is then filtered from the aqueous medium and washed with alcohol and dried. The resulting product has resinous properties and is suitable T for molding. In lieu of using methyl vinyl ketone, other ketones such as methyl isopropenyl ketone, methyl-a-methoxyvinyl ketone, methyla-ethoxyvinyl ketone, methyl-a-carbethoxyvinyl ketone, etc. may be used.

Example 6.Copolumer of acrylamide and 9- methylenefluorene 10 gms. of 9-methylenefluorene and 5 gms. of acrylamide are intimately mixed and dissolved in a 1:1- mixture of acetic acid and dimethyl 20 gms. of methyl methacrylate are added to 5 gms. of 9-methylenefiuorene and the mixture is copolymerized by heating at 60 C. in an atmosphere of nitrogen while using 0.5% benzoyl peroxide as a catalyst. The product thus obtained was molded with ease. When methyl methacrylate is replaced by such compounds as methacrylate, p-cyanoethyl acrylate, methyl .acrylate, methyl-a cyanoacrylate, .etc. other resinous copolymers may be obtained.

fumarate, and the solution polymerized as described in Example 4. Water is then added to the reaction product and a white product precipitates. This product is then filtered, washed with water and alcohol, and dried. The copolymer so obtained has resinous properties and is suitable for molding. -In lieu of acrylamide other olefinic amides such as a-methylacrylamide, a-acetoxyacrylamide, -carbomethoxyacrylamide, etc. may

. be used.

thepresence of 0.2 gm. of benzoyl peroxide as l0 gms. of 9-methylenefiuorene and 25 gms. of

dimethyl iumarate are intimately mixed and polymerized by heating at C.. for 48 hours in polymerization catalyst. The product so obtained is then digested with methanol and dried. A white residue remained which can be molded with heat. When diethyl fumarate diisopropyl fumarate, dimethyl maleate, cis-. and trans-fi-cyanomethyl acrylate, cisand trans-fl-carboxyamidoacrylate, etc. are substituted for the dimethyl fumarate above, other copolymers suitable for molding are obtained.

Example 8.--Copolymer of styrene and 9-methyl- 10 gms. of 9-methylenefiuorene and 10 gins. of styrene are intimately mixed and heated en masse in an atmosphere of nitrogen at a temperature of 60 C. in the presence of benzoyl peroxide as a polymerization catalyst. The product so obtained has resinous properties and is suitable for molding. In lieu of using styrene, other olefinic hydrocarbons such as dichloro or difiuoro styrene, a-carboxyamido styrene, p-acetaminostyrene, butadiene, chloropyrene, etc. may be used.

Example 9.C'opolymer of vinyl salfonamide, vinyl acetate, and Q-methylenefluorene 10 gms. of Q-methylenefluorene, 10 gins. of vinyl sulfonamide, and gins. of vinyl acetate are intimately mixed and polymerized en masse by heating as described in Example 8 above in the presence of benzoyl peroxide as a catalyst. A yellow, resinous solid which is suitable for molding results. In lieu of using vinylsulfonamide, other olefinic compounds of sulphur such as N- methylvinylsulfonamide, N-butyl-u -methylvinylsulfonamide, methylvinylsulfone, etc. may be used. In place of vinyl acetate other vinyl-type esters such as vinyl trifluoroacetate, vinyl benzoate, isopropenyl acetate, etc. may be used to advantage.

Erample 10.-Copolymer of ethylene and 9- methylenefluorene 10 gms. of Q-methylenefluorene are placed in a silver-lined, steel autoclave and 40 gms. hexane and 0.2 gm. of benzoyl peroxide added. Ethylene, under a pressure of 600 atmospheres is pumped into the reactor containing the Q-methylenefiuorene solution. The mixture is agitated and the temperature of the reactor raised to 125 C., heating is continued for 10 hours, and the reactor then cooled. The charge is removed from the reactor and the residue steam distilled and filtered. A resinous solid of tough texture is obtained which has valuable properties when molded. Other olefinic hydrocarbons such as propylene, piperylene, etc. may be used in lieu of ethylene.

Example J1.--C0polymer of vinylz'dene chloride, ethylene and .I-methylenefluorene In lieu of using pounds as vinyl chloride, isopropenyl chloride,

isopropenyl bromide, vinyl bromide, vinyl fluoride, etc.

8 Example 12.-Copolymer of acrvlonitrile and 9- methylenefluorene 10.6 g. (0.2 mol) 1.78 g. (0.01 mol) of 9-methylenefluorene, and 1.1 g. (0.1% by weight) of benzoyl peroxide are placed in a. glass ampoule. The ampoule is then cooled to approximately 10 C. and the air removed by evacuating with a vacuum pump. The ampoule is then flushed with nitrogen 3-4 times to remove any supernatant oxygen, and the ampoule then sealed. The ampoule is then placed in a water bath and heated at 50-60 C. until the contents become solid. The slightly yellowish, hard, tough polymer is then dissolved in dimethyl tormamide, and the solution poured into distilled water. The fine, almost white precipitate can be dissolved in dimethyl formamide, dimethyl acetamide, succinonitrile and spun into fibers.

Example 13.C'opolymer of acrylonitrile, Q-methylenefluorene and itaconic acid 10.6 g. of acrylonitrile (0.2 mol), 1.78 g. (0.01 mol) of 9-methylenefluorene, 0.65 g. (0.005 mol) of itaconic acid, and 1.3 g. (0.1% by weight) of benzoyl peroxide are placed in a sealed glass ampoule under an atmosphere of nitrogen as in Example 12. The ampoule is then placed in a water bath and heated at 50-60 C. until the contents become solid. The resulting yellowish solid is then dissolved in dimethyl i'ormamide and precipitated by pouring into water.

By substituting molecularly equivalent amounts of citraconic, mesaconic, acrylic, or a-methacrylic acids in the above example, other copolymers can be prepared.

Example 14.C'opolymer of methyl methacrylate and Q-methillenefluorene g. (1.0 mol) of methyl methacrylate. 8.9 g. (0.05 mol) of 9-methylenefluorene, and 1.5 g. of benzoyl peroxide are placed in a sealed glass ampoule under an atmosphere of nitrogen. The

ampoule is then placed in a water bath and heated at 50-60 C. until the contents become solid. The resulting polymer is dissolved in dimethyl formamide and precipitated by pouring into methanol.

By substituting molecularly equivalent amounts of ethyl methacrylate, n-propyl methacrylate, or n-butyl methacrylate in the above example, other copolymers can be prepared.

Example 15.Copolymers of methyl methacrylate and Q-methylenefluorene 59.3 g. (0.3 mol) of 9-methylenefluorene, 1.5 g. (0.015 mol) of methyl methacrylate, and 2.5 g. of benzoyl peroxide are placed in a sealed glass ampoule under an atmosphere of nitrogen as in Example 12. The ampoule is then placed in a water bath and heated at 50-60 C. until the contents of the ampoule become solid. The resulting hard polymer is dissolved in dimethyl tormamide and precipitated by pouring into water.

By substituting molecularly equivalent amounts of n-butyl acrylate, ethyl methacrylate, or n-propyl methacrylate in the above example, other copolymers can be prepared.

A particular advantage in our use of 9-methylenefluorene in preparing copolymers is that even when used in small amounts (e. g. as low as 2 mol percent) it has a profound eflfect on the solubility of the resulting polymers. For example. po yacrylonitrile can be dissolved in I g. dimethyl formamide, but not dimethyl aeetamidc. but when'no more than 2 mol-percent of iI-methylenefluorene is copolymerized with acrylonitrile;

the resulting polymer can be dissolved in dimethyl acetamide. Dimethyl acetamide is mach ne'- ferred to dimethyl formamide, due torits lower cost and lower toxicity. The advantages of the use of Q-methyleneflubrene become particularly apparent when it is desired to prepare films or fibers from the copolymersprepared in accordance with our invention.

Although we can advantageously only one or two unsaturated compounds in addition to the Q-methylenefluorene in a single copolymerization,

' of Q-methylenefluorene and 1:5 parts by weight oi methyl-a-acetoxyacrylate. a 3. 'A resinous copolymer of :1 parts by weigh of 9-methylenefluorene and'1:5 parts by weight of dimethyl fumarate.

4. A resinous copolymer of 9-methylenefluorene and a polymerizable, unsaturatedcompound selected from the group consisting of: (a) esters having. the formula: I

wherein R represents a member selected from the group consisting of hydrogen, a methyl group, and an acyloxy group of an aliphatic carboxylic acid having 2 to 4 carbon atoms, and R1 represents a member selected from the group consisting of an alkyl group having 1 to-4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, and an aralkyl' group; (b) nitriles'having the formula:

' capo-can wherein R2 represents a member selected from the group consisting of a hydrogen atom, a methyl group, and an acyloxy group of an aliphatic carboxylic acid having 2 to 4 carbon atoms. and (c) diesi'ers having the formula:

7 ture consi ing of 2 to 95 mol-percent of 9-methylenefluor e and 5 to 98 moi-percent of a poly-' merizable, unsaturated compound selected from the group consisting of: (a) esters having the formula:

acid ming e to'14 carbon atoms, and R1 represents a member selected from the group'consistqing of an alkyl group having 1&0 icarbonatoms,

' an alkenyl group having 2 to 4 carbon atoms, and

wherein R5 represents a member selected from the group consisting of a hydrogen atom, a methyl 1 grounand an acyloxy group of an aliphatic carboxylic'aciwhaving 2 to 4 carbon atoms, and

(c) =diesters having the formula: f

,- oyo Tao-tsunami m v wherein, R3 and R4 each represents a member selected from the group consisting ,of, an alkyl roup having 4 carbon atoms and an aralkyl ro p, Y

8, A resinous copolymer oi- 5:1 parts by weight oi 9-methylenefluorene and 1:5 parts by weight of an ester represented by the formula:

4 carbon atoms.

7. A resinous copolymer of 5:1, parts by weight of 9-methylenefluorene and 1:5 parts by weight pound selected from those represented y the formula: v

wherein R represents an acyloxy group of an aliphatic carboxylic acid having 2 to 4 carbon atoms and R1 represents an alkyl group ofthe formula Cal-I2": wherein n is a 'positive'lnteger from lto 4."

I 8. .A resinous copolymer of5z1'parts by weight oi il-methylenefluorene and 1:5 parts by weight I of a compound selected from those represented by the formula: v

wherein R. represents a member selected from the group consisting of hydrogen, a methyl group,

wherein R1 represents an alkyl group of the formula CamIH-I wherein n isa positive integer from 1 to 4. Y

9. A resinous copolymer of 5:1 parts by weight of Q-methylenefiuorene and 1:5 parts by weight of an ester representedby the formula:

o ,0. p aio- -clkcn- -on.

wherein R5 and R4 eachrepresents an alkyl group ture consisting of 5: 1 partsby weight of 9-methylof an ester.

'enefluorene andilz5 parts by weight represented'by the formula:

wherein! representsan alkyl group having 1 to 4 carbon atoms.

11. A process for preparing resinous copolymers which comprises polymerizing in the presonce oi a peroxide polymerisation catalyst a mixture consisting oi 5:1 parts by weight of 9-methyleneiluorene and 1:5 parts by weight of a compound selected from those represented by the formula:

obi-Loni 12 eneiiuorene and 1:5 parts by weight of an ester represented by the formula:

0 o RlOAOH=OH-8OBI wherein R: and R4 each represents an alkyl group of the formula Celia wherein n is a positive integer from 1 to 4. JOSEPH B. DICKEY.

HARRY W. COOVER, Jr.

REFERENCES CITED The following references are of record in the tile of this patent:

Sieglitz et a1.: Ber. 553, 2032- (1922); abst. in Chem. Abst., 17, 386-8! (1923).

Ferrer: Anales soc. espan. 11s. quim. 20, 459-66 (1922), abst. in Chem. Abst., 17, 3177 (1923).

Wieland et al.: Ber. 553, 3313-7 (1922); abst. in Chem. Abst., 17, 754' (1923).

Wieland et al.: Ann. 530, 274-99 (1937); abst. in Chem. Abst., 32, 137 (1938). 

4. A RESINOUS COPOLYMER OF 9-METHYLENEFLUORENE AND A POLYMERIZABLE, UNSATURATED COMPOUND SELECTED FORM THE GROUP CONSISTING OF: (A) ESTERS HAVING THE FORMULA; 